PDP-11 Still Working In Nuclear Plants - For 37 More Years 336
Taco Cowboy writes "Most of the younger /. readers never heard of the PDP-11, while we geezers have to retrieve bits and pieces of our affairs with PDP-11 from the vast warehouse inside our memory lanes."
From the article: "HP might have nuked OpenVMS, but its parent, PDP-11, is still spry and
powering GE nuclear power-plant robots and will do for another 37 years. That's right: PDP-11 assembler programmers are hard to find, but the nuclear industry is planning on keeping them until 2050 — long enough for a couple of generations of programmers to come and go." Not sure about the OpenVMS vs PDP comparison, but it's still amusing that a PDP might outlast all of the VAX machines.
Re:That's just cruel (Score:4, Informative)
Re:I cut my teeth on that CPU (Score:5, Informative)
The microcontrollers are not rad-hardened. The PDP with core memory and 54-series TTL logic will probably survive a small nuclear blast. There are no highly vulnerable EMI susceptable components in a PDP that I can think of. In fact, I think the military has used (does use?) this and the earlier DTL technologies in its missile computers.
Can doesn't mean should (Score:4, Informative)
These days you can probably replace them with Arduinos.
Theoretically true but not necessarily a good idea. The equipment installed is already known to work and whatever issues it has are probably very well understood. Any installation of new hardware is going to bring new bugs and a nuke plant isn't exactly a place you want to beta test things if you don't have to. Plus there are a host of operational certification issues in play. I get why they haven't "upgraded" the hardware.
On the other hand I'm a little bit surprised (only a little) that doing things this way is the most economical method available, even accounting for the risk involved with updating systems.
Re:I cut my teeth on that CPU (Score:4, Informative)
What were you doing chewing on the CPU? You're supposed to lick them.
Some like to be chewed, some like to be licked. It depends on the model.
Re:That's just cruel (Score:5, Informative)
So? A "generation" is commonly held to be 30 years; the average child (note: not first-born) being born when the parents are approximately 30. Secondly, TFA specifies two generations "coming and going", which means two ENTIRE generations pass; not just one passing and the second one beginning.
That is 60 years, not 37 years. TFS, if not TFA, which I didn't read, is officially stupid.
Commonly by who?
In virtually all cases, generations are pegged at 20 years. The common "Gen X", "Gen Y", etc are all 20 year spans. In fact, virtually every named "generation" of the last century were equal or slightly less than 20 years.
Even if you go by the average age of first birth, in virtually all of the "1st world", its right around 25. The peak averages are barely 30, and globally its in the low 20's, depending on the source.
So by either definition, there's definitely time for two generations ... and if you're talking about the average time in a given position (which is a more meaningful generation when speaking about engineers), you're looking at more like 15 years -- or time for three.
Re:I cut my teeth on that CPU (Score:4, Informative)
Yeah, I wouldn't be surprised. People nowadays would be surprised at what you can do with low clock speeds, a simple instruction set, and TTL logic. For basic control functions there's no need for anything too fancy and every extra transister is just another thing that can go wrong. Most avionics systems are still using 1970's era 16 bit processors. They've gotten a lot cheaper, but mostly there's just no need for anything fancier when the job is "monitor these 8 DACs and these 5 discrete inputs in a tight loop, apply this filter, write the results to this UART, and close this valve if the state machine reaches this point", lol.
Re:I cut my teeth on that CPU (Score:3, Informative)
If the airconditioning broke down in the machine room, we had about 15 minutes to shut everything down before the temperature hit 50 degrees C. [OT: Why, oh why, can
The company I worked for got rid of that machine in 1978 (in favour of a Honeywell DPS7), but I remember reading in some computing magazine in 1988 that NASA (IIRC) had ordered several of these machines. I can't find any reference to it now, so that might have been shitcanned. It wasn't very long after that, in any case, that Burroughs merged with Sperry (another of my earlier platforms) to form Unisys.
Re:Dave Cutler's work lives on (Score:5, Informative)
Microsoft hired him to lead a team that designed Windows NT.
Wow. Way to re-write history. No, I'm afraid that's not how it went down. Dave Cutler developed what ultimately is NT while working for Digital Equipment Corporation. DEC wasn't interested in Dave's creation. Dave unethically and possibly illegally shopped it around. Microsoft was interested. Dave and his entire engineering team left DEC, and went to work for Microsoft, and actually, literally stole DEC's intellectual property and eventually released it as Windows NT. Yes, I am saying that Windows NT is the intellectual property of Digital Equipment Corporation, and Microsoft never paid DEC a red nickel for it.
On a personal note, I am divided about Mr. Cutler. Windows NT might have been the best Windows ever, and NT itself isn't a terrible platform. What Microsoft did to it is unfortunate for users and administrators everywhere, but it essence, NT wasn't terrible. Cutler is an impressive developer... quite amazing... yet it sickens me that what he and Microsoft did was insanely unethical, and no one noticed. Microsoft's main flagship product was STOLEN, and no one noticed, and this is hardly ever acknowledged.
Re:If it ain't broke... (Score:5, Informative)
So what's your point? Want reliability: don't use a PC. Got it.
But that doesn't mean the PDP/11 is the only reliable system ever and "they don't build them like that anymore". You can get modern machines in MILSPEC if you want to pay for them . But you don't need to go that far. INDUSTRIAL-grade is good enough.
And honestly, I trust a good PLC, say, Siemens (I have no experience with american brands), to be more reliable than a 40 year old PDP, no matter how well built it was. Siemens has been making automation controls for a LONG time and their products are really good, and I'll guess most of their bugs have been solved in all these years.
As for PLC programming, remember they're not done in "code", but rather in "Ladder Diagram" so they can be well-understood, and have a graphical representation of the process, which is usually more easy to understand than thousands of lines of code.